Linking Single Event In-Orbit Data to Space Weather

Abstract

Correctable single event upsets observed in a SRAM memory on-board of Sentinel 2A and 2B are studied, with the aim of identifying a correlation between space weather activity and the orbital time and position of occurrence of SEU. Sentinel 2A and 2B are two identical ESA satellites flying at an average altitude of 786 km. The SRAM memory under study is part of the memory system supervisor. Event rate, sampled at one orbital period, is heavily superim-posed by normal variance due to intrinsic Poisson distribution of SEE. A moving average filter extracts features attributed to the solar cycle, the South Atlantic Anomaly (SSA) seasonal behaviour and device degradation. Further data is needed to study the response to geomagnetic storms, since available ones are relative to a prolonged 'solar lull' period. Position data is filtered similarly, which is expected to show the movement of the SAA as seen by single events. The two satellites' filtered event positions show common features, but also peculiar, currently unexplained, short-term differences.